package linklist;

/**
 * @author Jonny Long
 * @date 2021/2/2 8:17
 */
public class Solution141 {
    public boolean hasCycle(ListNode head) {
        if (head==null || head.next==null){
            return false;
        }
        ListNode slow=head;
        ListNode fast=head.next;
        while (slow!=fast){
            if (fast==null || fast.next==null){
                return false;
            }else {
                slow=slow.next;
                fast=fast.next.next;
            }
        }
        return true;
    }
}
